Rotating seal configuration and method of sealing a rotating member to a housing

ABSTRACT

A seal configuration includes a housing and a rotatable member rotationally mounted relative to the housing. The rotatable member has at least one portion defining an outer perimetrical face that is configured to contact the housing during operational conditions that cause a radial dimension of the at least one portion to increase. The at least one portion has opposing axial surfaces with each of the opposing axial surfaces being dimensionally axially nearer to the other of the opposing axial surfaces immediately radially inwardly of the outer perimetrical face than a furthest part of the outer perimetrical face.

BACKGROUND OF THE INVENTION

The subject matter disclosed herein relates to configurations that seala rotating member to a housing and more specifically to sealing anoutermost radial portion of the rotating member to the housing. Sealingcomponents that move relative to one another create challenges. Thesechallenges are exacerbated when clearance between the moving componentsis altered based upon operational conditions of the machine as happensbetween a shroud of a bucket and a casing of a turbine engine, forexample. Industries that rely on such seals are therefore receptive tonew systems and methods that improve sealing between parts movingrelative to one another.

BRIEF DESCRIPTION OF THE INVENTION

According to one aspect of the invention a rotating seal configurationincludes a housing and a rotatable member rotationally mounted relativeto the housing. The rotatable member has at least one portion definingan outer perimetrical face that is configured to contact the housingduring operational conditions that cause a radial dimension of the atleast one portion to increase. The at least one portion has opposingaxial surfaces with each of the opposing axial surfaces beingdimensionally axially nearer to the other of the opposing axial surfacesimmediately radially inwardly of the outer perimetrical face than afurthest part of the outer perimetrical face.

According to another aspect of the invention a method of sealing arotatable member to a housing includes rotating a rotatable memberrelative to a housing, contacting the housing with a portion of therotatable member and cutting a groove in the housing with the portionwhile preventing contact between either of opposing axial surfaces ofthe portion and the housing.

According to another aspect of the invention a turbomachine componentincludes a rotatable member rotationally mounted relative to a housing.The turbomachine component has a portion defining an outer perimetricalface being configured to contact the housing during some operationalconditions, the portion has opposing axial surfaces that are axiallynearer to one another at positions radially inwardly of the outerperimetrical face than they are at the outer perimetrical face.

These and other advantages and features will become more apparent fromthe following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter, which is regarded as the invention, is particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features, and advantages ofthe invention are apparent from the following detailed description takenin conjunction with the accompanying drawings in which:

FIG. 1 depicts a cross sectional view of an embodiment of a rotatingseal configuration disclosed herein;

FIG. 2 depicts a cross sectional view of an alternate embodiment of arotating seal configuration disclosed herein; and

FIG. 3 depicts a partial cross sectional view of a turbine engineemploying a plurality of the rotating seal configurations of FIG. 1 or2.

The detailed description explains embodiments of the invention, togetherwith advantages and features, by way of example with reference to thedrawings.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, an embodiment of a rotating seal configurationdisclosed herein is illustrated at 10. The rotating seal configuration10 includes a substantially stationary housing 14 and a rotatable member18 that is configured to rotate relative to the housing 14. Therotatable member 18 has a portion 22 with an outer perimetrical face 26located at the greatest radial dimensions thereof. The outerperimetrical face 26 is configured to interferingly contact the housing14 during certain operational conditions of a machine that incorporatesthe housing 14 and the rotatable member 18. The portion 22 has opposingaxial surfaces 30, 31 positioned immediately radially inwardly of theouter perimetrical face 26. The rotating seal configuration 10 isconfigured such that one or both of the opposing axial surfaces 30, 31is axially nearer to the other of the opposing axial surfaces 30, 31immediately radially inwardly of the outer perimetrical face 26 than afurthest part 32, 33 of the outer perimetrical face 26.

Contact between the portion 22 and the housing 14 while the rotatablemember 18 is rotating causes the portion 22 to cut into the housing 14thereby cutting an annular groove 34 into an inner radial surface 38 ofthe housing 14. The cutting of the groove 34 assures that annularclearance between the outer perimetrical face 26 and the housing 14 isreduced thereby forming a dynamic seal therebetween. Materials for thehousing 14 and the portion 22 may be chosen to assure that more materialis removed from the housing 14 than from the rotatable member 18 duringcutting. In turbine engine applications, for example, the housing 14 isoften made of thin metal sheets in the shape of honeycomb cells whilethe rotatable member 18 is fabricated of much thicker metal. As such thehoneycomb housing 14 is sacrificial and is easily cut away by therotatable member 18 when the portion 22 comes into contact therewith.The portion 22 in a turbine engine may be part of a shroud of a bucketor one of two or more teeth in a labyrinth seal of a rotor while thehousing may be a stationary outer assembly of the turbine engine oranother rotatable part that rotates at a different speed than that ofthe portion 22, for example.

Making the opposing axial surfaces 30, 31 nearer to one anotherimmediately radially inwardly of the outer perimetrical face 26 than afurthest part 32, 33 of the rotating seal configuration 10 assures thatthe opposing axial surfaces 30, 31 do not come into contact with sides42 of the groove 34. Such contact, if allowed to occur could havedetrimental operational effects related to frictional engagement,heating and removal of additional material from either the housing 14 orthe rotatable member 18 beyond that which is necessary, for example.

If the interference contact between the portion 22 and the housing 14 isdue to radial growth only of the rotatable member 18 the sides 42 willbe substantially orthogonal to a rotational axis of the rotatable member18. If there is some longitudinal movement combined with the radialgrowth of the rotatable member 18 the sides 42 may have a frustoconicalor even a curved conical shape. If a longitudinal component of motion isanticipated then the opposing axial surfaces 30, 31 can be made torecede axially a sufficient amount to assure they do not contact thehousing 14 when cutting thereinto. It should be noted that theinterference contact between the portion 22 and the housing 14 can alsobe due to a reduction in radial dimension of the housing 14.

Angles 46 and 47 are defined between the outer perimetrical face 26 andthe opposing axial surfaces 30, 31 respectively. In the embodimentillustrated the outer perimetrical face 26 is parallel to a rotationalaxis of the rotatable member 18 (it should be noted, however, that outerperimetrical surfaces that are not parallel to the rotational axis ofthe rotatable member 18 are also possible). The angles 46 and 47 areless than 90 degrees and are therefore acute angles. Since the rotatablemember 18 in FIG. 1 is tilted, for example, and is not perpendicular toa rotational axis of the rotatable member 18, sides 50, 51 thereof arealso tilted. As such, the opposing axial surface 30 can simply be anextension of the side 50 thereby defining a portion of the acute angle46. However, if the opposing axial surface 31 were simply an extensionof the side 51 then the angle 47 would be obtuse and would measuregreater than 90 degrees. Opposing axial surface 31 is therefore not anextension of the side 51 but instead is a recess in the portion 22between the side 51 and the outer perimetrical surface 26. Since theopposing axial surface 31 is a recess it can be made in the rotatablemember 18 by removal of material from the rotatable member 18, which iseasier to fabricate than adding material to a rotatable member as istypically done.

Referring to FIG. 2, an alternate embodiment of a rotating sealconfiguration disclosed herein is illustrated at 110. The configuration110 is similar to the configuration 10 and as such similar features arenumbered alike and only differences will be described in detailhereunder. The rotatable member 118 of the rotating seal configuration110 has sides 150, 151 that taper together toward the outer perimetricalsurface 26. As such, both opposing axial surfaces 130, 131 are definedby recesses formed in the sides 150, 151 at a portion 122 of rotatablemember 118 near the outer perimetrical surface 26, thereby definingacute angles 146, 147 respectively.

Referring to FIG. 3, a portion 212 of a turbine engine 216 employing therotating seal configuration 10, 110 disclosed herein. The portion 212can be any rotating portion 212 of the turbine engine 216 including butnot limited to rotational portions of a compressor section or a turbinesection. The portion 212 includes a plurality of the rotating sealconfigurations 10, 110 with one configuration 10, 110 each beingillustrated on an end 220 of one of five teeth 224. Together theplurality of rotating seal configurations 10, 110 form a labyrinth seal228 since each of the teeth 224 form one of the grooves 34 in thehousing 14.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

1. A rotating seal configuration, comprising: a housing; and a rotatablemember rotationally mounted relative to the housing having at least oneportion defining an outer perimetrical face being configured to contactthe housing during some operational conditions, the at least one portionhaving opposing axial surfaces with at least one of the opposing axialsurfaces being dimensionally axially nearer to the other of the opposingaxial surfaces immediately radially inwardly of the outer perimetricalface than a furthest part of the outer perimetrical face.
 2. Therotating seal configuration of claim 1, wherein the outer perimetricalface is oriented substantially parallel to a rotational axis of therotatable member.
 3. The rotating seal configuration of claim 1, whereinan angle between the outer perimetrical face and each of the opposingaxial surfaces is acute.
 4. The rotating seal configuration of claim 1,wherein the outer perimetrical face cuts into the housing in response tocontact therewith while the rotatable member is rotating.
 5. Therotating seal configuration of claim 1, wherein the rotating sealconfiguration is configured such that neither of the opposing axialsurfaces make contact with the housing after the rotatable member hascut a groove into the housing.
 6. The rotating seal configuration ofclaim 1, wherein the at least one portion is a plurality of the at leastone portion that together form a labyrinth seal with grooves cut intothe housing.
 7. The rotating seal configuration of claim 1, wherein theat least one portion is a labyrinth seal of a turbine engine.
 8. Therotating seal configuration of claim 1, wherein the at least one portionis part of a shroud of a turbine bucket.
 9. The rotating sealconfiguration of claim 1, wherein the housing has a honeycomb structure.10. The rotating seal configuration of claim 1, wherein greatest radialdimensions of the at least one portion define the outer perimetricalface.
 11. The rotating seal configuration of claim 1, wherein at leastone of the opposing axial surfaces is formable by removal of materialfrom a side of the rotatable member.
 12. The rotating seal configurationof claim 1, wherein a radial dimension of the at least one portionincreases during some operational conditions.
 13. A method of sealing arotatable member to a housing, comprising: rotating a rotatable memberrelative to a housing; contacting the housing with a portion of therotatable member; and cutting a groove in the housing with the portionwhile preventing contact between either of opposing axial surfaces ofthe portion and the housing.
 14. A turbomachine component, comprising arotatable member rotationally mounted relative to a housing having atleast one portion defining an outer perimetrical face being configuredto contact the housing during some operational conditions, the at leastone portion having opposing axial surfaces that are axially nearer toone another at positions radially inwardly of the outer perimetricalface than they are at the outer perimetrical face.
 15. The turbo machinecomponent of claim 14, wherein the turbomachine component is employed ina turbine engine.
 16. The turbo machine component of claim 15, whereinturbomachine component is part of a compressor section of the turbineengine.
 17. The turbo machine component of claim 15, whereinturbomachine component is part of a turbine section of the turbineengine.
 18. The turbo machine component of claim 14, wherein the atleast one portion is a plurality of portions.
 19. The turbo machinecomponent of claim 18, wherein each of the plurality of portions forms agroove in the housing.
 20. The turbo machine component of claim 19,wherein the plurality of portions and the plurality of grooves togetherform a labyrinth seal.